Feat: Add warning for conflicting group permissions

This change introduces a visual warning in the group settings page. The warning appears when an admin attempts to disable a permission for a group that is already enabled in the default 'user' group. This is necessary because permissions are additive, and disabling a permission in a specific group will not revoke it if it's enabled in the default group.

To achieve this, the following changes were made:
- A new `PermissionSwitch.svelte` component was created to encapsulate the permission switch and its warning logic, avoiding redundant code.
- The `Groups.svelte` component was updated to correctly fetch the default user group's permissions.
- The `Permissions.svelte` component was refactored to use the new `PermissionSwitch.svelte` component, making the code cleaner and more maintainable.

src/lib/components/admin/Users/Groups/EditGroupModal.svelte

@@ -21,6 +21,7 @@
 
 	export let users = [];
 	export let group = null;
+	export let defaultPermissions = {};
 
 	export let custom = true;
 
@@ -230,7 +231,7 @@
 							{#if selectedTab == 'general'}
 								<Display bind:name bind:description />
 							{:else if selectedTab == 'permissions'}
-								<Permissions bind:permissions />
+								<Permissions bind:permissions {defaultPermissions} />
 							{:else if selectedTab == 'users'}
 								<Users bind:userIds {users} />
 							{/if}